There is a need to impart antimicrobial activity to mattresses, covered box springs and similar bedding articles that are subject to the potential for mold growth or mildew and/or in contact with and contamination by various substances. Bedding products used under high humidity conditions such as prevalent in various Pacific rim countries have been constructed of fabrics treated to resist mold growth. This is particularly advantageous for fabric-covered bedding products not readily laundered or otherwise cleaned. This invention provides an improved process for imparting antimicrobial properties to textile coverings for such bedding products and other uses.
This invention relates to a process for imparting antimicrobial properties to textile fabrics by applying an antimicrobial substance to the fibers from which the textile is woven, knit or constructed. Preferably the antimicrobial substance is applied, prior to weaving, to warp yarns on a slasher or warper or similar coating or finish application device before the warp ends are rolled up onto a loom or section beam. The warp yarns are then woven with fill yarns, not treated with the antimicrobial, into a cloth which is then sold in the loom state or subjected to subsequent finishing. A preferred cloth end use is mattress ticking.
We have found that treating the warp yarns only and not the fill yarns and thereafter weaving the treated yarns together with untreated weft or fill yams into a cloth is sufficient to impart the desired antimicrobial properties of inhibiting the growth of bacteria and fungi in and to the woven product. This process of antimicrobially treating warp yams only is more efficient and less costly than treating or finishing woven fabric in a pad bath in open width. The antimicrobial substance is applied in an economical manner with minimal mixing and processing and results in only small quantities of unused or otherwise unsuited materials. Such bioactive materials when expended and discharged often require controlled environmental handling and waste disposal processing.
The fibers of the yarns to be treated by this process may be in filament or spun yam form, textured such as false twisted or not. The fibers may be cellulosic-based fibers such as cotton, rayon or linen, or synthetic fibers such as nylons, polyesters, polyolefins such as polypropylene and the like as well as natural protein fibers such as wool or silk, or may be blended yarns containing two or more types of fibers, particularly cotton/polyester or cotton/nylon blends. Preferably the fibers used to form the warp are robust such as polyester or spun rayon yarn while the fill may be a less robust fiber such as cotton, rayon or polypropylene. The warp yams subjected to antimicrobial treatment according to this process may be slashed/sized, slasher dyed or unsized yams prior or subsequent to antimicrobial application.
The antimicrobial applied to the warp yams preferably has both bacterostatic and fungistatic properties and thus imparts to the finished fabric resistance to bacterial growth and fungal growth sufficient to inhibit the growth of mildew and associated deterioration and discoloration as well as inhibiting microbial odor development. Suitable antimicrobial compositions are available to the textile industry from various suppliers and are approved for use on textiles by the Environmental Protection Agency. These include 5-chloro-2(2,4-dichlorophenoxy)phenol also known as triclosan manufactured by Sanitize AG and marketed by Clariant Corporation of Charlotte, NC as Sanitized(copyright) T96-21. Sanitized(copyright) XTX, manufactured by Sanitized AG and marketed by Sanitize, Inc. is also effective when applied in this manner. Both products are an anionic antimicrobial agent effective against gram positive and gram negative bacteria, fungi and yeast. The agent is biostatic against mold, mildew and the like and acts to prevent offensive odors resulting from bacterial decomposition of absorbed perspiration. Another commercially available product is Bioshield available as an aqueous solution of octdecylaminodimethyltrimethoxysilylpropyl ammonium chloride, methanol, and chloropropyltrimethoxysilane. This product is manufactured by Bioshield Technologies Inc of Norcross, Georgia and distributed by a number of firms including Apollo Chemical of Burlington, NC. The Bioshield product is a cationic organosilane compound which is claimed to be effective on gram positive and negative bacteria, fungi and algae. It is EPA approved for mattress pads and ticking.
The choice of antimicrobial agent depend to the type or types of odor-causing or textile fabric discoloring/degrading microbes encountered where the textile product is used. Agents active against dust mites may also be considered.
The antimicrobial substance is applied to the yarn by any suitable means such as by a slasher of the type typically used for applying size. Preferred is an over-oiler of the type used to apply weaving aid lubricants to warp yarns. The antimicrobial substance is conveniently in the form of liquid, preferably in an aqueous solution or dispersion. Also present in the solution, suspension or dispersion may be ancillary components used by the product manufacturer to control pH, stability, solubility, viscosity, product concentration, and wetting characteristics. These products will differ upon the type of antibacterial agent used in the application and the concentration of the active ingredient in the product used. Additional components may be combined with the antimicrobial products as purchased to modify or add to properties such as concentration of active ingredient, ability to kill other microorganisms such as dust mites, modification of the warp to improve processing characteristics such as weaving efficiency, and modification of the warp to improve aesthetic properties of the finished fabric.
The amount of antimicrobial to be applied can be adjusted as required by changing the pulley which ties the speed of the over-oiler application wheel to the speed at which the yarn runs through the slasher. Finishing processes include various backcoatings to impart resistance to fraying, flame retardency, and improved sewing characteristics and various heat and pressure treatments to improve the finished appearance of the face of the fabric.
In a preferred aspect of the invention the antimicrobial product is applied xe2x80x9cneatxe2x80x9d (not diluted) in concentrated formulations available from the supplier to one side of a yarn sheet which is subsequently rolled up- transferring application to the other side of the sheet. This method is very efficient with respect to antimicrobial product usage and the thus coated yams require no subsequent drying thereby eliminating additional processing steps. Other, more widely used methods such as those typically recommended by the suppliers of antimicrobial finishes require that the material be diluted, padded onto already woven fabric and subsequently dried or that they be applied from an aqueous dyebath in an exhaust dyeing process. Both of these methods require a drying step and involve more waste of material. The waste in the procedures of our invention is virtually nil as the antimicrobial composition is applied only to the warp yarns in an efficient application device such as an over-oiler.